FR2769028A1 - C=section pile and driving procedure for forming wall - Google Patents

Abstract

The pile (2) is made from concrete reinforced with a frame of transverse (21) C-shaped and lengthwise (22) straight metal rods and end members. It is driven into the ground via. a hole drilled from a platform, and a series of piles is positioned so that the slot of one lies against the back of another to form a continuous wall. The cavities of the piles are then filled with concrete.

Description

C-SHAFT AND METHOD OF DRIVING THE C-SHAFT
Field of the invention
The present invention relates to a method of driving C piles into the earth in order to produce a construction such as a retaining wall and a basement wall.

The conventional methods used to produce the above-mentioned constructions frequently pose the following problems
1. The increase in the size of
constructions is accompanied by
increase in the size of the
construction. These large machines can
however hardly be used in
reduced spaces and have large
disadvantages in terms of vibration and
of sound emissions.

2. The increase in the size of
constructions results in a
increased volumes to be excavated and
time required for excavation work
as well as worsening problems
landslide near the holes.

3. It is difficult to build walls
underground in agglomerates.

4. The evacuation of liquid sludge is
problematic.

5. Water and / or soil infiltrate frequently
between the stakes.

6. It is difficult to remove the mud
flowing below the base of the piles
7. It is difficult to control the quality of
concrete in water.

Summary of the invention
The main object of the present invention is to provide a method of driving C-piles in the ground with a view to carrying out a construction by solving the aforementioned problems.

 The process for building a continuous wall includes the following steps: having a C-pile, drilling a hole in the ground, inserting the C-pile in the hole, repeating the previous steps to drive other C-piles contiguously then pour concrete into the C piles. The C piles are thus assembled to form a continuous wall.

Brief description of the drawings
Figure 1 is a side view of a C pile according to an embodiment of the present invention, part of the concrete having been omitted in order to expose the internal reinforcement
Figure 2 is a cross-sectional view of the C-shaped pile of Figure 1
Figure 3 is a side view of a C pile according to a second embodiment of the present invention, part of the concrete having been omitted in order to expose the internal reinforcement
Figure 4 is a cross-sectional view of the C-shaped pile of Figure 3
Figure 5 is a side view of a pile according to a third embodiment of the present invention, part of the concrete having been omitted in order to expose the internal reinforcement
Figure 6 is a cross-sectional view taken along line 6-6 of Figure 5
Figure 7 is a side view of a pile according to a fourth embodiment of the present invention, part of the concrete having been omitted in order to expose the internal reinforcement
Figure 8 is a cross-sectional view taken along line 8-8 of Figure 7
Figure 9 is a side view of a bucket type drill
Figure 10 is a top view of the bucket type drill shown in Figure 9
Figure 11 is a side view of a worm type drill.

Figure 12 is a top view of a platform for facilitating the driving of the pile in C according to Figures 1 and 2
Figure 13 is a side view established along arrow A of Figure 12
Figure 14 is a side view established along arrow B of Figure 12
Figure 15 is a top view of the platform in operation
Figure 16 is a side view taken along arrow C of Figure 15
Figure 17 is a side view taken along arrow D of Figure 15
Figure 18 is a top view of a construction composed of C piles as shown in Figures 1 and 2
Figure 19 is a top view of a construction composed of piles C as shown in Figures 1 and 2 and piles C as shown in Figures 3 and 4; and
FIG. 20 is a perspective view of a construction made of piles C as shown in FIGS. 1 and 2.

Detailed description of preferred execution modes
Figures 1 and 2 illustrate a C 2 pile according to an embodiment of the present invention.

This C 2 pile takes the form of a tube comprising a slot 25 formed from one of its ends at the opposite end and internally defining a cylindrical space 26. The C 2 pile is open at its two ends.

 The pile in C 2 consists of a metal frame (not marked) and a concrete body (not marked) poured on said metal frame.

The metal frame comprises transverse bars 21, longitudinal bars 22, two end plates 23 and bar positioning elements 24. Each bar positioning element 24 has orifices receiving the longitudinal bars 22 in order to maintain the latter in position relative to each other. The cross bars 21 are connected to the longitudinal bars 22. The end plates 23 are assembled at the ends of the longitudinal bars 22. The cross bars 21, the end plates 23 and the bar positioning elements 24 are all shaped as C so as to obtain a C 2 pile by pouring the concrete body onto the metal frame.

 Referring now to Figures 3 and 4, there is shown a pile C 3 according to a second embodiment of the present invention.

This C 3 pile is identical to the C 2 pile except for two flat faces 31 added on either side of the slot 25. The flat faces 31 are parallel to each other. When the C 3 piles are dark in the ground, their planar faces 31 constitute two opposite planar faces of larger surface (see fig. 19). Since the manufacture of C 3 piles is similar to that of C 2 piles, it will not be described in detail.

 Figures 5 and 6 show a pile 4 according to a third embodiment of the present invention. The pile 4 is obtained by adding an auxiliary reinforcement 40 to the pile at C 2 illustrated in FIGS. 1 and 2.

 The auxiliary frame 40 comprises auxiliary transverse bars 41, auxiliary longitudinal bars 42 and auxiliary bar positioning elements 43. The auxiliary transverse bars 41 are identical to the transverse bars 21 except that they are smaller dimension and have two different ends. Thus, each auxiliary crossbar 41 assumes the shape of the Greek letter "Q". The auxiliary longitudinal bars 42 are identical to the longitudinal bars 22. The auxiliary bar positioning elements 43 are identical to the bar positioning elements 24 except that they are of smaller dimensions.

 When the pile 4 is produced, the auxiliary bar positioning elements 43 are fixed to the bar positioning elements 24. Each auxiliary bar positioning element 43 has orifices receiving the auxiliary longitudinal bars 42. The auxiliary transverse bars 41 are connected to the auxiliary longitudinal bars 42.

 In the embodiment shown in Figures 5 and 6, each bar positioning element 24 and each auxiliary bar positioning element 43 can be produced separately and then connected by welding or any other suitable means. However, in another embodiment (not shown), they can be made in one piece.

 In the embodiment shown in FIGS. 5 and 6, the ends of the auxiliary transverse bars 41 are connected to the longitudinal bars 22 by welding, connection using a metal wire or any other suitable means.

However, in another embodiment (not shown), the ends of the auxiliary transverse bars 41 can be connected to the transverse bars 21 and not to the longitudinal bars 22.

Each of the transverse bars 21 and each of the auxiliary transverse bars 41 can be produced separately and connected by welding, bonding using a metal wire or any other suitable means. Alternatively, they can also be made in one piece.

 The diameter of the auxiliary reinforcement 40 is substantially less than that of the cylindrical space 26 so that the auxiliary reinforcement 40 of a pile 4 can be inserted into the cylindrical space 26 of another pile 4. A wall made with piles 4 is more resistant to forces tending to separate said piles than a wall made with piles in C 2.

 Referring to Figures 7 and 8, there is shown a pile 5 according to a fourth embodiment of the present invention. This pile 5 is obtained by adding an auxiliary reinforcement 40 to the pile at C 3. The manufacture of piles 5 is similar to that of piles 4 except that the pile at C 2 is replaced by the pile at C 3 It will therefore not be the subject of a detailed description.

 Several piles have been described according to different embodiments of the present invention with reference to Figures 1 to 8; other configurations are however possible. The expression "C pile" refers to a pile having a substantially circular internal edge interrupted by a cut in a cross-sectional view. The external periphery of the C pile can therefore assume any suitable shape.

 Referring to Figures 9 and 10, there is shown a bucket type drill 6 according to the present invention. Said bucket type drilling machine 6 comprises a bucket 60, an upper cover 62 and a lower cover 63. The external diameter of the bucket 60 is substantially less than that of cylindrical space 26 so that the bucket 60 can be moved in space cylindrical 26. The open upper end of the cup 60 can be closed by the upper cover 62. The open lower end of the cup 60 can be closed by the lower cover 63. An opening 68 is defined in the cup 60. Teeth 65 are integral with a blade 67 formed on the bucket 60. When the bucket type drill 6 is in rotation, the ground is broached and discharged into the bucket 60 via the blade 67 and the opening 68. An axis 61 protrudes from the upper cover 62 for connection to a drilling spindle (not shown). A drill bit 66 protrudes from the lower cover 63. The teeth 64 protrude from the lower cover 63.

 A worm-type drill 7 according to the present invention is illustrated in FIG. 11. The worm-type drill 7 has an axis 72, a propeller 73 extending on the axis 72, teeth 74 integral from the lower end of the propeller 73, a blade 76 projecting transversely from the axis 72 and teeth 75 being integral with said blade 76. The teeth 75 are intended to broach the ground around a hole intended to receive the pile 2 or 3. The distance between the center of the axis 72 and the free end of the blade 76 is equal to the external radius of pile 2 or 3.

 FIGS. 12 to 14 show a platform 8 making it possible to keep the pile at C 2 vertical and to lower it to a speed corresponding to the driving speed of the drill 6 or 7. The platform 8 comprises an upper plate 81 and a lower plate 82 both having a pile passage opening intended to receive the pile at C 2.

 The lower plate 82 is connected, on its lower face, to four hydraulic cylinders 83 making it possible to bring said lower plate 82 into a horizontal position.

The upper plate 81 is connected to the lower plate 82 by four hydraulic cylinders 84 making it possible to move said upper plate 81 on the lower plate 82. A pile guide structure 86 is formed on the upper plate 81 so as to be oriented vertically when the upper plate 81 is in a horizontal position. The pile guide structure 86 extends over the periphery of the pile passage opening, formed in the upper plate 81. The internal face of the pile guide structure 86 coincides with the external face of the pile at C 2 , so that the pile guide structure 86 can keep the C 2 pile vertical. The pile guide structure 86 is advantageously made with an adequate height to effectively ensure the vertical holding of the piles at C 2. A pile lifting device (85, 88) connects the upper plate (81) to the piles at
C (2) to raise and lower the piles at C (2).

In the pile guide structure 86 two slots 88 are defined.

 Two hydraulic cylinders 85 are connected on either side of the pile guide structure 86. Each hydraulic cylinder 85 is connected at one of its ends to the pile guide structure 86 and can be connected to the other end, at the C 2 pile. To connect the hydraulic cylinders 85 to the C 2 pile, a pin (not shown) is engaged in housings (not shown) provided on the hydraulic cylinders 85, in the slots 88 and in the orifices (not shown) defined in the pile at C. The pile at C 2 can thus move along a vertical path under the effect of the hydraulic cylinders 85.

 The method for driving the piles at C 2 will be described below in support of FIGS. 15 to 17.

 The platform 8 is initially brought into a horizontal position by means of the hydraulic cylinders 83. A C 2 pile is mounted movably on the platform 8 as described in the preceding paragraph.

 The blade 67 (or 76) is aligned with the slot 25 so that the drill 6 (or 7) can be moved through the cylindrical space 26. The drill 6 is lowered until it is about 30 to 50 cm in below the pile in C 2. The blade 67 then being below the pile in C 2, the drill 6 can be started in order to drill a hole in the ground.

 As the drill 6 digs into the ground, the C 2 pile is lowered to support the periphery of the hole. During the driving of the C 2 pile, the periphery of the hole comprises two parts not supported by said C 2 pile. The first unsupported part is aligned with the slot 25.

This unsupported first part, however, has enough consistency so as not to collapse for some time before being removed when driving the next C 2 pile. The second unsupported part is located below the pile in C 2. This second unsupported part, however, also has enough consistency not to collapse for some time before being supported by the pile, in C 2 which is lowered. In order to ensure that the second unsupported part does not collapse, its length cannot exceed 30 to 50 cm; that is to say that the C 2 pile is held 30 to 50 cm upstream of the drill 6.

 Since each pile has a limited length, it may sometimes be necessary to connect several piles axially to reach the desired depth. To this end, once a C 2 pile is dark in the ground at the desired depth, another C 2 pile is lowered until it comes to axially abut against the previous C 2 pile. The terminal elements 23 of the piles at C 2 are then assembled by suitable means, in particular by welding.

 When a C 2 pile is dark in the ground, its open lower end is closed, as described below with reference to FIG. 20.

 If there is a little water in the hole, low-slump concrete is poured into the bottom of the hole and then vibrated to remove the soft ground or the mud from the C 2 pile. The low-slump concrete then forms a base pile 9 which closes the open lower end of the pile C 2 while increasing the surface supporting the loads.

 If there is a lot of water in the hole, it should be evacuated before closing the open lower end of the pile at C 2. If there is always a little water left in the hole, infiltration, the low slump concrete is bagged before being introduced to the bottom of the hole in order to exclude the risk of dilution. It is then vibrated to drive the liquid mud and water out of the C 2 pile. The low-slump concrete forms a pile base 9.

 Once the pile base 9 has been formed, the above-mentioned steps are repeated in order to drive other C 2 piles into the ground in order to produce a construction as shown in FIG. 18.

 To make a resistant construction, the cylindrical spaces 26 should be filled with concrete as described below. When all the piles in C 2 are dark, the soil and / or the mud adhering to the internal faces of the said piles are removed with compressed air and / or with water. The water is then evacuated from the cylindrical spaces 26. The C 2 piles can then be inspected in order to detect any residual space between two adjacent C 2 piles. In the absence of residual space, the concrete is poured directly into the C 2 piles. Otherwise, the concrete is bagged before being introduced into the poorly sealed C 2 pile. This measure therefore makes it possible to control the quality of the concrete.

 If the construction shown in FIG. 18 is subjected to significant dislocation forces, it is advantageous to replace the C 2 piles with C 4 piles. In this case, only the first pile is a C 2 pile, the other piles being piles 4. In addition, the piles 4 situated at the corners of the construction all include an auxiliary reinforcement offset by an angle of 900 relative to the position shown in FIG. 6.

 Figure 19 shows a construction made of C 2 and 3 piles. The piles located at the corners of the construction are C 2 piles, while the other piles are C 3 piles.

 When the construction illustrated in FIG. 19 is subjected to significant dislocation forces, the C 2 piles are replaced by 4 piles and the C 3 piles by 5 piles.

 When a C 2 pile is tilted to the point where it prevents the next C 2 pile from driving, it can be partially drilled when the next pile is driven, to avoid the formation of a space between two piles. C 2 misaligned.

Advantages of the invention
The present invention solves the aforementioned problems encountered in the prior art by proposing a pile driving method having the following advantages
1. The piles according to the present invention
can be darkened with small
gear even when it comes to making
large constructions. Small machines
have the double advantage of being
practices and generate low
vibrations and low noise emissions.

2. The driving of a pile according to the present
invention only requires drilling
in the earth from a small hole
dimension. To make big
foundations, before digging a large
hole in the ground it is possible to
form an underground wall by sinking
piles according to the present invention. This
measure excludes any risk
subsidence.

3. The drill according to the present invention
makes it easy to build walls
underground in agglomerates.

4. Liquid sludge can be easily
evacuated from the holes.

5. The piles can be assembled so
contiguous to constitute a wall resistant to water.

6. The mud under the stake is easy to
clear out.

7. The quality of concrete is easy to control.

Claims (8)

 1. C pile characterized in that it comprises an internal cylindrical space (26), a longitudinal slot (25) as well as an open upper end and an open lower end.  2. C pile according to claim 1, characterized in that it comprises a metal frame embedded in a concrete body, said metal frame comprising  a) a plurality of positioning elements  C-shaped bars (24), each  of said elements having a plurality  orifices  b) a plurality of longitudinal bars  (22), each inserted into a hole in  one of the positioning elements of  bars (24) C-shaped, so that  ensure the positioning of said bars  longitudinal (22)  c) a plurality of transverse bars (21)  C-shaped, connected to bars  longitudinal (22); and  d) two C-shaped end elements (23)  firmly assembled at the ends of the  longitudinal bars (22).  3. C pile according to claim 1, characterized in that it comprises two flat lateral parts, formed on its outer periphery.  4. C pile according to claim 1, characterized in that it comprises on its external periphery a tubular metallic network.  5. pile driving method characterized in that it comprises the following steps  a) provide a platform (8) oriented  horizontally,  b) provide a pile in C (2) comprising a  internal cylindrical space (26), a slot  longitudinal (25) and one end  upper open and one end  lower open  c) mount the pile at C (2) mobile  vertically on the platform (8); -  d) provide a drill (6, 7) below the  stake in C (2) and operate said  drill (6, 7) so as to dig a hole  In the ground  e) by means of the platform (8), guide the  C pile (2) inside the drilled hole  In the ground  f) close the open lower end of the  C pile (2)  g) repeat steps a) to f) in order to darken  a plurality of C piles (2) in the  earth to make a wall  underground; and  h) fill the cylindrical spaces (26) with  concrete.  6. Method according to claim 5, characterized in that the platform (8) comprises  a) an upper plate (81) provided with a  opening allowing the passage of piles  in C (2);  b) a lower plate (82) provided with a  opening allowing the passage of piles  in C (2)  c) a first adjustment device (83) for  support and adjust the plate  lower (82) so that it is  included in a horizontal plane  d) a second adjustment device (84) connected  to the upper plate (81) and to the plate  lower (82)  e) a projecting guide structure (86)  on the upper plate (81) and arranged  around the opening of the tray  upper (81); and  f) a pile lifting device (85, 88)  connecting the upper plate (81) to the piles  in C (2) to raise and lower the  C piles (2).  7. Method according to claim 5, characterized in that the drilling machine is of the bucket type (6) and comprises  a) a cup (60) provided with an opening (68),  an open upper end and a  open lower end, the bucket (60)  being movable in the cylindrical space  (26)  b) a blade (67) projecting transversely from the  bucket (60) so as to move in the  slot (25) when the bucket (60) is  displaced in the cylindrical space (26)  c) a plurality of teeth (65) integral with  the blade (67)  d) an upper cover (62) for sealing  the open upper end of the  bucket (60)  e) a pin (61) projecting from the cover  upper (62) for connection to a  drilling spindle  f) a lower cover (63) for sealing  the open lower end of the  bucket (60)  g) a drill (66) projecting from the cover  lower (63); and  h) a plurality of teeth (64) projecting towards  the bottom of the lower cover (63).  8. Method according to claim 5, characterized in that the drilling machine (7) is of the worm type and comprises  a) an axis (72)  b) a propeller (73) winding around  the axis (72);  c) a plurality of teeth (74) integral  from a lower end of  the propeller (73);  d) a blade (76) projecting transversely from  the axis (72); and  e) a plurality of teeth (75) integral with  the blade (76).